Devices for cooling the nasal cavity

ABSTRACT

A method for cerebral cooling is described using a cooling assembly, which includes first and second elongate tubular members adapted for insertion into a nasal cavity of a patient through the patient&#39;s nostrils. The elongate tubular members each have a proximal end, a distal end, a lumen extending therebetween, and a plurality of ports in fluid communication with the lumen. The cooling assembly also includes a manifold and a reservoir, which contains a pressurized fluid that includes a propellant having a boiling point less than 22° C. The elongate tubular members are inserted into the nasal cavity through the patient&#39;s nostrils and pressurized fluid is delivered onto a surface of the nasal cavity by infusing the pressurized fluid from the reservoir through the manifold, into the lumens and through the plurality of ports of the first and second elongate tubular members.

This application is a continuation of U.S. application Ser. No.13/963,238, filed Aug. 9, 2013, which is a continuation of U.S. Ser. No.13/439,772, entitled “Devices for Cooling the Nasal Cavity,” filed Apr.4, 2012. now U.S. Pat. No. 8,512,280, which is a divisional of U.S. Ser.No, 12/819,116, entitled “Devices for Cooling the Nasal Cavity,” filedon Jun. 18, 2010, now U.S. Pat. No. 8,157,767, which claims the benefitof U.S. provisional patent application Ser. No. 61/218,774, entitled“Device for Cooling the Nasal Cavity,” filed Jun. 19, 2009, all of whichare expressly incorporated herein by reference in their entirety for allpurposes.

FIELD OF THE INVENTION

The invention relates to cerebral and systemic cooling via the nasalcavity, oral cavity, and other parts of the body, and more particularlyto methods and devices for cerebral and systemic cooling using liquidsor liquid mists and for delivering liquid mists to the nasopharyngealcavity.

BACKGROUND OF THE INVENTION

Patients experiencing cerebral ischemia often suffer from disabilitiesranging from transient neurological deficit to irreversible damage(stroke) or death. Cerebral ischemia, i.e., reduction or cessation ofblood flow to the central nervous system, can be characterized as eitherglobal or focal. Global cerebral ischemia refers to reduction of bloodflow within the cerebral vasculature resulting from systemic circulatoryfailure caused by, e.g., shock, cardiac failure, or cardiac arrest.Within minutes of circulatory failure, tissues become ischemic,particularly in the heart and brain.

The most common form of shock is cardiogenic shock, which results fromsevere depression of cardiac performance. The most frequent cause ofcardiogenic shock is myocardial infarction with loss of substantialmuscle mass. Pump failure can also result from acute myocarditis or fromdepression of myocardial contractility following cardiac arrest orprolonged cardiopulmonary bypass. Mechanical abnormalities, such assevere valvular stenosis, massive aortic or mitral regurgitation,acutely acquired ventricular septal defects, can also cause cardiogenicshock by reducing cardiac output. Additional causes of cardiogenic shockinclude cardiac arrhythmia, such as ventricular fibrillation. Withsudden cessation of blood flow to the brain, complete loss ofconsciousness is a sine qua non in cardiac arrest. Cardiac arrest oftenprogresses to death within minutes if active interventions, e,g.,cardiopulmonary resuscitation (CPR), defibrillation, use of inotropicagents and vasoconstrictors such as dopamine, dobutamine, orepinephrine, are not undertaken promptly. The most common cause of deathduring hospitalization after resuscitated cardiac arrests is related tothe severity of ischemic injury to the central nervous system, e.g.,anoxic encephalopathy. The ability to resuscitate patients of cardiacarrest is related to the time from onset to institution of resuscitativeefforts, the mechanism, and the clinical status of the patient prior tothe arrest.

Focal cerebral ischemia refers to cessation or reduction of blood flowwithin the cerebral vasculature resulting in stroke, a syndromecharacterized by the acute onset of a neurological deficit that persistsfor at least 24 hours, reflecting focal involvement of the centralnervous system. Approximately 80% of the stroke population ishemispheric ischemic strokes, caused by occluded vessels that deprivethe brain of oxygen-carrying blood. Ischemic strokes are often caused byemboli or pieces of thrombotic tissue that have dislodged from otherbody sites or from the cerebral vessels themselves to occlude in thenarrow cerebral arteries more distally. Hemorrhagic stroke accounts forthe remaining 20% of the annual stroke population. Hemorrhagic strokeoften occurs due to rupture of an aneurysm or arteriovenous malformationbleeding into the brain tissue, resulting in cerebral infarction. Othercauses of focal cerebral ischemia include vasospasm due to subarachnoidhemorrhage from head trauma or iatrogenic intervention.

Current treatment for acute stroke and head injury is mainly supportive.A thrombolytic agent, e,g., tissue plasminogen activator (t-PA), can beadministered to non-hemorrhagic stroke patients. Treatment with systemict-PA is associated with increased risk of intracerebral hemorrhage andother hemorrhagic complications. Aside from the administration ofthrombolytic agents and heparin, there are no therapeutic optionscurrently on the market for patients suffering from occlusion focalcerebral ischemia. Vasospasm may be partially responsive to vasodilatingagents. The newly developing field of neurovascular surgery, whichinvolves placing minimally invasive devices within the carotid arteriesto physically remove the offending lesion, may provide a therapeuticoption for these patients in the future, although this kind ofmanipulation may lead to vasospasm itself.

In both stroke and cardiogenic shock, patients develop neurologicaldeficits due to reduction in cerebral blood flow. Thus treatments shouldinclude measures to maintain viability of neural tissue, therebyincreasing the length of time available for interventional treatment andminimizing brain damage while waiting for resolution of the ischemia.New devices and methods are thus needed to minimize neurologic deficitsin treating patients with either stroke or cardiogenic shock caused byreduced cerebral perfusion.

Research has shown that cooling the brain may prevent the damage causedby reduced cerebral perfusion. Initially research focused on selectivecerebral cooling via external cooling methods. Studies have also beenperformed that suggest that the cooling of the upper airway can directlyinfluence human brain temperature, see for example Direct cooling of thehuman brain by heat loss from the upper respiratory tract, Zenon Mariak,et al. 8750-7587 The American Physiological Society 1999, incorporatedby reference herein in its entirety. Furthermore, because the distancebetween the roof of the nose and the floor of the anterior cranial fossais usually only a fraction of a millimeter, the nasal cavity might be asite where respiratory evaporative heat loss or convection cansignificantly affect adjacent brain temperatures, especially becausemost of the warming of inhaled air occurs in the uppermost segment ofthe airways. Thus, it would be advantageous to develop a device andmethod for achieving cerebral cooling via the nasal and/or oral cavitiesof a patient.

SUMMARY OF THE INVENTION

The invention relates to methods and devices for providing cerebral andsystemic cooling via the nasal cavity. The cooling occurs by direct heattransfer through the nasal cavity and/or nasopharynx as well as byhematogenous cooling through the carotids as they pass by the oropharynxand through the Circle of Willis, which lies millimeters away from thepharynx. The direct cooling will be obtained through evaporative heatloss of a nebulized liquid in the nasal cavity. Additionally, coolingmay occur through convection in the nasal cavity. Such cerebral coolingmay help to minimize neurologic deficits in treating patients witheither stroke or cardiogenic shock caused by reduced cerebral perfusionor in the treatment of migraines. In the following description, where acooling assembly, device, or method is described for insertion into anostril of a patient, a second cooling assembly or device can optionallyalso be inserted into the other nostril to maximize cooling.

In one embodiment, the invention provides a method for cerebral coolingvia the nasal cavity using a self-contained cooling and delivery system.A cooling assembly including an elongate tubular member having aproximal end, a distal end, a first lumen extending therebetween, aplurality of ports in fluid communication with the first lumen and asecond lumen extending between proximal and distal ends, the secondlumen communicating with a balloon mounted on the first elongate tubularmember distal the plurality of ports is provided. The cooling assemblyalso includes a manifold in fluid communication with the first andsecond lumens of the elongate tubular member and further communicatingwith a second elongate tubular member which is also in fluidcommunication with a reservoir containing a pressurized fluid via thesecond elongate tubular member. The elongate tubular member is insertedinto a nasal cavity of a patient through the patient's nostril such thatthe balloon and plurality of ports are positioned in the nasal cavity.The balloon is inflated by infusing fluid and/or pressure from thereservoir through the manifold and into the second lumen. Thepressurized fluid is then delivered onto a surface of the patient'snasal cavity by infusing the pressurized fluid from the reservoirthrough the manifold into the first lumen and through the plurality ofports. The fluid preferably comprises a refrigerant having a boilingpoint of 37° Celsius or below such that it will evaporate upon contactwith the nasal cavity surface. The evaporation of the fluid from thenasal cavity preferably results in reduction of the cerebral temperatureof the patient by at least 0.5° C. in one hour. Alternatively, thecerebral temperature may be reduced by at least 1.0° C. in one hour,alternatively at least 1.5° C. in one hour, alternatively at least 2° C.in one hour, alternatively at least 2.5° C. in one hour, alternativelyat least 3° C. in one hour, alternatively at least 4° C. in one hour,alternatively at least 5° C. in one hour, alternatively at least 6° C.in one hour, alternatively at least 7° C. in one hour. A pressurerelease valve in the manifold may be activated to deflate the balloon atthe completion of the delivery of fluid to the nasal cavity.Alternatively, if additional cooling is desired, a second pressurizedfluid container may be connected to the manifold to continue treatment.

In another embodiment, the invention provides a self-contained coolingassembly including a pressurized fluid source that is capable ofdelivering a cooling fluid that evaporates in to a patient's nasalcavity and automatically inflating an occluding balloon located on thedistal end of the cooling assembly using pressure from the pressurizedfluid source. The cooling assembly includes a first elongate tubularmember adapted for insertion into the nasal cavity of a patient, amanifold and a reservoir containing a pressurized fluid. The firstelongate tubular member has proximal and distal ends, first and secondlumens extending therebetween, a plurality of ports located in thedistal region in fluid communication with the first lumen, and a balloonmounted on the elongate tubular member distal the plurality of ports influid communication with the second lumen. The manifold is in fluidcommunication with the first and second lumens of the elongate tubularmember and a second tubular member which is in fluid communication withthe reservoir such that pressurized fluid passes from the reservoir,through the manifold, and into the second lumen to inflate the balloonand into the first lumen and through the plurality of ports.

In use, the elongate member is inserted into a nasal cavity of a patientthrough one of the patient's nostrils and positioned in the nasalcavity. The elongate member may be positioned in the nasal cavity suchthat the balloon on the distal end of the elongate member will contactthe walls of the posterior nasal cavity and form a seal between thenasal cavity and the patient's nasopharynx when inflated. Alternatively,the elongate tubular member may be positioned such that the balloon willcontact the nasopharynx and form a seal between the nasal cavity and thepatient's nasopharynx when inflated. The ports on the distal region ofthe elongate member will then be positioned to deliver a nebulizedliquid spray over the surface of the nasal cavity, including the nasalplexus and the carotids. The proximal end of the elongate member isplaced in fluid communication with a pressurized fluid source via amanifold. Pressure from the pressurized fluid source is used to pushliquid and/or vapor from the pressurized fluid source into the elongatetubular member. The manifold controls delivery of the fluid to theelongate member such that liquid and/or vapor is first delivered througha lumen in fluid communication with the balloon mounted on the distalend of the elongate member to inflate the balloon. Once the balloon hasbeen inflated, a check valve in the manifold opens and allows the fluid,including both liquid and vapor, to be delivered though a second lumenin fluid communication with the ports located on the distal region ofthe elongate member. A liquid spray is delivered into the patient'snasal cavity through the plurality of ports. In one embodiment, theliquid is nebulized at each of the plurality of ports on the elongatemember. The fluid has a boiling point equal to or less than 37° Celsiussuch that a majority of the fluid will be delivered in liquid form andwill evaporate upon contact with the surface of the nasal cavity. Someof the fluid though will evaporate during transit and become vapor.Cooling will be both from the vapor, which is chilled from theevaporation that created it, and also from the liquid spray as itevaporates in the nasal cavity. The volume of liquid delivered from asingle pressurized canister may be range from about 0.05 to about 1Liter. For example, it is envisioned that a single pressurized canistercould deliver about 50 mL of cooling liquid, alternatively about 100 mL,alternatively about 200 mL, alternatively about 0.5 Liters,alternatively about 0.75 Liters, alternatively about 1 Liter of coolingliquid. Depending on the cooling fluid used, these volumes of coolingfluid may provide cooling for approximately 10 minutes, alternatively upto 30 minutes, alternatively up to one hour. In addition, it is furtherenvisioned that additional cooling time may be provided, if needed, byattaching additional canisters to the cooling assembly. The inflatedballoon prevents unevaporated fluid from being inhaled by the patient.In some embodiments, the unevaporated fluid may also be suctioned orotherwise removed from the patient's nasal cavity via a suction lumen inthe elongate tubular member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of a device having a pressurized sourcefor delivering a fluid to the nasal cavity according to the presentinvention for non-invasive cerebral and systemic cooling.

FIG. 2 illustrates an embodiment or a device having a pressurized sourcefor delivering a fluid to the nasal cavity according to the presentinvention for non-invasive cerebral and systemic cooling.

FIG. 3 illustrates an alternative embodiment of a device having apressurized source for delivering a fluid to the nasal cavity accordingto the present invention for non-invasive cerebral and systemic cooling.

FIG. 4A illustrates an embodiment of a manifold for use with a devicehaving a pressurized source for delivering a fluid to the nasal cavityaccording to the present invention for non-invasive cerebral andsystemic cooling.

FIG. 4B illustrates a check valve in the manifold of FIG. 3B allowingpressure to move distally when the manifold is pressurized.

FIG. 4C illustrates a check valve in the manifold of FIG. 3B preventingpressurized fluid from flowing proximally when the manifold is notpressurized.

FIG. 4D illustrates the manifold of FIG. 3A manually released to relievepressure in the device.

FIG. 5 illustrates an embodiment of the distal end of a nasal cathetertube for use with the cooling assembly for delivering a fluid to thenasal cavity for non-invasive cerebral and systemic cooling.

FIG. 6 illustrates a cross-section of the nasal catheter tube for usewith the cooling assembly for delivering a fluid to the nasal cavity fornon-invasive cerebral and systemic cooling.

FIG. 6 illustrates a cross-section of an embodiment of the nasalcatheter tube for use with the cooling assembly for delivering a fluidto the nasal cavity for non-invasive cerebral and systemic cooling.

FIG. 7 illustrates a cross-section of an alternative embodiment of thenasal catheter tube for use with the cooling assembly for delivering afluid to the nasal cavity for non-invasive cerebral and systemiccooling.

FIG. 8 illustrates a cross-section of an alternative embodiment of thenasal catheter tube for use with the cooling assembly for delivering afluid to the nasal cavity for non-invasive cerebral and systemiccooling.

FIG. 9 illustrates an embodiment of a cooling assembly having apressurized fluid source inserted into a patient's naval cavity fordelivering a fluid to the nasal cavity for non-invasive cerebral andsystemic cooling.

FIG. 10 illustrates an alternative embodiment of a cooling assemblyhaving a pressurized fluid source inserted into a patient's naval cavityfor delivering a fluid to the nasal cavity for non-invasive cerebral andsystemic cooling.

DETAILED DESCRIPTION

Described herein are devices and methods for delivering, from apressurized source, a fluid that evaporates in the nasal cavity toprovide cerebral and or systemic cooling. The approach is a selfcontained methodology which is designed for emergent care at the site ofthe injury. Essentially, this process provides a device and method forrapidly administering therapeutic hypothermia in an out-of-hospitalsetting, such as by emergency or ambulance personnel by developing anendothermic reaction within the nasal pharyngeal space, a mini-internalrefrigeration unit. This approach eliminates the need for externalrefrigeration units, and large ventilation units which are not portable.

The device includes at least one nasal catheter in fluid communicationwith a pressurized fluid source for delivering a liquid spray of thefluid, which has a boiling point equal to or less than body temperature.In some embodiments, the device includes two nasal catheters such thatone nasal catheter is positions within each of a patient's nostrils tomaximize cooling. The device also has a balloon(s) on the distal end ofthe nasal catheter(s) that is inflated from some of the pressure fromthe pressurized source. In this device, the balloon(s) is inflated andthe fluid is delivered to the nasal cavity using the pressure from thepressurized fluid source without the use of pumps or electronics. Byusing a pressure from the pressurized fluid source to inflate theballoon and deliver the fluid to the nasal cavity, the approach furtherimproves the ease of use and portability of the cooling assembly.

The purpose for the fluid is to cool the nasal cavity, which in turncools the brain. The purpose for the balloon(s) is to keep most, if notall, un-evaporated fluids or gases from being inhaled or swallowed bythe patient. The cooling fluid may be any refrigerant having a boilingpoint of 37° Celsius or less. Fluids having a boiling point at or belowbody temperature, i.e., 37° Celsius, will evaporate upon contact withthe walls of the nasal cavity without the need to deliver an additionalgas to enhance evaporation. For example, the cooling fluid may be, butis not limited to, a perfluorocarbon, a fluorocarbon, ahydrofluorocarbon, or any mixture thereof, having a boiling point ofapproximately 37° Celsius or less. In some embodiments, a propellanthaving a boiling point at or below room temperature, i.e., approximately22° Celsius, may be used to pressurize the fluid reservoir in order todeliver the cooling fluid to inflate the balloon and cool the nasalcavity. The propellant may also be, but is not limited to, aperfluorocarbon, a fluorocarbon, a hydrofluorocarbon, having a boilingpoint at or below approximately 22° Celsius. The propellant may be mixedin with the fluid in the fluid reservoir or alternatively, the fluid andpropellant may remain separated in the pressurized fluid reservoir. Forexample, the cooling fluid may be provided in a separate bladdersurrounded by the propellant, as known in the art, to prevent mixing ofthe propellant and cooling fluid. Alternatively, the cooling fluid mayhave a boiling point at or below approximately 22° Celsius, such thatthe cooling fluid can function as the propellant as well.

The patient's cerebral, systemic and/or nasal temperatures may bemonitored during this process. The liquid spray may be delivered at arate sufficient to achieve a gradient of not more than 0.5° Celsiusbetween the outer surface of the brain and the inner core of the brain.The liquid spray may also be delivered at a flow rate sufficient toachieve a gradient of at least about 1.0° Celsius between the cerebraltemperature and systemic temperature. The liquid spray may also bedelivered at a flow rate sufficient to achieve cerebral cooling at arate greater that about 1.0° Celsius in one hour. The liquid spray mayalso be delivered at a flow rate sufficient to achieve a temperature inthe nasal cavity of about 4.0° Celsius. In some embodiments, the liquidspray may be nebulized at each of the plurality of ports just prior tobeing delivered to the nasal cavity.

FIGS. 1-2 illustrate an embodiment of a self-contained system fordelivering a fluid to the nasal cavity of a patient for providingcerebral and or systemic cooling. The cooling system includes apressurized fluid source, a delivery assembly, and a cooling assembly.The pressurized fluid source includes a pressurized container 10 filledwith a fluid 13 to be delivered to the nasal cavity and, optionally, aseparate propellant. The container 10 may be an aerosol type containeror any general pressure container, as known in the art. In someembodiments, the container 10 includes a propellant 14 having a boilingpoint less than room temperature for pressurizing the container anddelivering the fluid 13. Alternatively, the boiling point of the fluid13 may be at or below room temperature such that evaporation of some ofthe fluid itself may be used to pressurize the container and deliver thefluid. When a separate propellant is provided, the propellant and fluidare provided in a ratio sufficient to ensure that all the fluid ispushed out of the container.

The container body is of a hollow, cylindrical shape and constructed ofa material able to withstand the pressure from the contents. Thecontainer is preferably sized to provide a volume of cooling fluidranging from about 0.05 Liters to about 1 Liter. For example, it isenvisioned that a single pressurized container could deliver about 50 mLof cooling liquid, alternatively about 100 mL, alternatively about 200mL, alternatively about 0.5 Liters, alternatively about 0.75 Liters,alternatively about 1 Liter of cooling liquid, Depending on the coolingfluid used, these volumes of cooling fluid may provide cooling forapproximately 10 minutes, alternatively up to 30 minutes, alternativelyup to one hour. Moreover, in some embodiments, more than one containermay be used to provide additional cooling time.

The top of container 10 has a cap 11 which includes a valve, such as apush-down valve stem, that is in fluid communication with a dip tube 13extending to the bottom of the container 10. The cap 11 also has anoutlet channel in fluid communication with the valve assembly. Theoutlet channel is in fluid communication with a tubular member 60connecting the pressurized fluid source 10 to the cooling assembly. Thecap 11 may be depressed, turned, or otherwise actuated to open the valveconnecting the dip tube 12 and tubular member 60. Opening the valve willallow the pressure from the propellant, or fluid vapor, 14 to force thefluid 13 through the dip tube 12 and into the tubular member 60 fordelivery to the cooling assembly. In some embodiments, depressing orturning the cap may lock the valve into an open position. The cap 11 maybe pressed again or turned back to close the valve, for example, to stopdelivery of the fluid to tubular member 60 in the event that coolingneeds to be interrupted or terminated. In some embodiments, the cap 11may also contain a fluid flow controlling device, such as a needle typevalve or a variable diameter aperture to adjust the flow rate of fluidinto tubular member 60. Here, the cap 11 may include a selector whichwould allow the operator to choose one of several choices for the flowrate, for example, low flow, medium flow, high flow.

Tubular member 60 is connected to a delivery assembly comprising amanifold 20, check valve 22 and tubular members 41 and 51 extending fromthe manifold 20 for directing the delivery of the fluid 13 from thepressurized source 10 to one or more nasal catheters positioned in apatient's nasal cavity. As shown in FIGS. 4A-D, manifold 20 has an inletchannel 62 and two outlet channels 43 and 53. In use, inlet channel 62is connected to tubular member 60 to receive fluid from the pressurizedsource. Outlet channel 53 is connected to tubular member 51 fordelivering pressure and/or fluid 13 through a lumen of one or more nasalcatheters to inflate a balloon on the distal end of the catbeter(s).Outlet channel 43 is connected to tubular member 41 for delivering fluid13 through a lumen of one or more nasal catheters and onto the surfacesof the nasal cavity. As shown in FIG. 4B, when the manifold 20 ispressurized, i.e., by liquid flowing through inlet 62 from thepressurized source 10, the liquid 13 pushes down on valve plug 27 toprovide a path for allowing fluid 13 to flow thorough the manifold 20and outlet channels 43 and 53 into tubular members 41 and 51. As shownin FIG. 4C, when the manifold 20 stops being pressurized, for examplewhen the pressurized source 10 is removed or the valve thereon isclosed, spring 28 is released causing the plug 27 to block passage offluid and/or pressure from flowing in a distal, or reverse, directionfrom outlet channels 43 and 53. This allows an operator to exchangepressurized canisters, for example, if more cooling is desired, withoutdeflating the balloons(s) on the distal end(s) of the nasal catheter(s).As shown in FIG. 4D, the manifold 20 also has a release button 21connected to a pressure relief valve 23. Pressing down on the releasebutton 21 pushes down on valve 23 and valve plug 27 to provide apassageway through vents 29 a,b for pressure from outlet channels 43 and53. The release button 21 enables the operator to release excesspressure to prevent a build up of pressure in the balloon(s) in fluidcommunication with outlet channel 51. In addition, by allowing pressureto flow distally from outlet channel 51 out relief vents 29 a,b, therelease button 21 may be used to control the amount of inflation of theballoon(s) and/or to deflate the balloon(s) once the treatment has beencompleted. In some embodiments, the pressure relief valve mayalternatively be combined with the valve on the pressurized fluidcontainer 10 so that there is one button for initiating cooling and onebutton for deflating the balloons at the completion of cooling.

As shown in FIGS. 1-2, tubular members 41 and 51 are connected to twomulti-lumen nasal catheters 30 a,b to deliver fluid from the pressurizedsource 10 to balloons 50 a,b on the distal end of the catheters 30 a,band through ports 40 a,b to a patient's nasal cavity. A check valve 22in tubular member 41 prevents fluid from being delivered to the nasalcatheter lumens connected to the delivery ports 40 a,b on the nasalcatheters 30 a,b until the balloons 50 a,b have been fully inflated tosubstantially occlude the nasal cavity. The check valve 22 remainsclosed until the pressure from the pressurized source 10 exceeds theballoon inflation pressure. Thus, the fluid initially flows throughtubular member 51 and into the nasal catheter lumens connected toballoons 50 a,b to inflate the balloons 50 a,b. In some embodiments,fluid 13 from the pressurized fluid source 10 may flow through tubularmember 60, manifold 20 and tubular member 51 into the nasal catheterlumens and balloons 50 a,b. Once the fluid 13 enters the larger volumeof the balloons 50 a,b it will evaporate into the volume to inflate theballoon. Alternatively, as shown in FIG. 2, some embodiments may includea second pressure line 61 from the pressurized fluid source 10. Thepressure line 61 is connected to the top of pressurized fluid container10 so that it will be in fluid communication with the propellant orfluid vapor and not the liquid 13. Thus, the pressure line 61 can beused to deliver pressure to tubular member 51 to inflate the balloons 50a,b and tubular member 60 can be used to deliver fluid 13 throughdelivery ports 40 a,b and to the patient's nasal cavity. Once thepressure exceeds the pressure required for balloon inflation, checkvalve 22 opens to allow fluid to flow through tubular member 41 and intothe nasal catheter lumens connected to delivery ports 40 a,b.

In some embodiments, as shown in FIGS. 1 and 2, the cooling assembly maycomprise two multi-lumen nasal catheters 30 a,b each having anexpandable member 50 a,b mounted on the distal end and a plurality ofdelivery ports 40 a,b located in the distal region proximal to theballoons 50 a,b for delivering the cooling fluid to each of a patientsnostrils. Nasal catheters 30 a,b have a length sufficient to extendthrough the patient's nasal cavity to the posterior nasal cavity oralternatively into the patient's nasopharynx. The plurality of deliveryports 40 a,b are spaced apart longitudinally and axially along the outerwalls of catheters 30 a,b and distributed around the circumference ofthe catheter and spaced apart to cover the distance from about 3 cm toabout 12 cm along the length of catheters 30 a,b to deliver a liquidspray that substantially covers the surface of the patient's nasalcavity. Expandable members 50 a,b, such as a flexible balloon aremounted circumferentially about the distal end of nasal catheters 30 a,bare sized such that, upon expansion, they will fill the adjacent anatomyand create a seal.

In embodiments wherein the cooling assembly comprises two nasalcatheters, as show in FIGS. 1-2, tubular member 51 may branch into twoseparate channels 52 a,b for connecting to inflation lumens in eachnasal catheter 30 a,b. Likewise, tubular member 41 may branch into twoseparate channels 42 a,b for connecting to fluid delivery lumens in eachnasal catheter 30 a,b. Check valve 22 is located before tubular member41 branches into tubular members 42 a,b. A connection manifold 25connects channels 42 a,b and 52 a,b to the inflation and delivery lumensof each of the nasal catheters 30 a,b. Alternatively, as shown in FIG.1, the connection manifold 25 may connect channel 42 a and 52 a todelivery tube 32 a and channels 42 b and 52 b to delivery tube 32 a.Delivery tubes 32 a and 32 b can then be connected to nasal catheters 30a,b via a nasal manifold 26, which is designed to angle the nasalcatheters 30 a,b to provide patient comfort and better access to thenasal cavity. in other embodiments, the manifolds may be combined tosimplify assembly and/or to reduce cost. For example, manifold 22 withsplitter channels and pressure release valve 21 can be incorporated intothe pressurized fluid source 10 so that there is one button to initiatecooling and another button to deflate the balloons for removal.Additionally or in the alternative, the connection manifold 25 can beincorporated into the nasal manifold 26.

In use, as shown in FIG. 9 (illustrating use in one nostril), each ofthe dual catheters 30 a,b of the cooling assembly are advanced into thepatient's nostrils 102 such that balloons 50 a,b are positioned in theposterior aspect of the patient's nasal cavity 101. In this embodiment,the balloons 50 may be positioned on either side of the nasal cavitybefore the septum. Fluid and/or pressure from the pressurized source 10is delivered to the balloons 50 a,b and the balloons 50 a,b are inflatedto conform to the posterior aspect of the nasal cavity 101 and form aseal isolating the nasal cavity 100 from the nasopharynx 104 and therest of the patient's airways in order to prevent non-vaporized liquid13 from leaking into the pharynx. Once isolated, a spray of liquid 13may be delivered through delivery ports 40 a,b into the patient's nasalcavity 101 and circulated though the nasal cavity 101 to allow for rapidcooling of the patient's head. The delivery ports 40 a,b are designed tocause the liquid spray to spread in a pattern that will cover as much ofthe surface of the nasal cavity 101 as possible. In addition, thedelivery ports 40 a,b are designed to nebulize the liquid just prior tothe liquid exiting the delivery ports 40 a,b. Some of the fluid 13though will evaporate during transit through the delivery system andbecome vapor. Thus, cooling will be provided by both the vapor, which ischilled from the evaporation that created it, the liquid spray as itevaporates in the nasal cavity. The volume of liquid delivered from asingle pressurized canister may be range from about 0.05 to about 1Liter. For example, it is envisioned that a single pressurized canistercould deliver about 50 mL of cooling liquid, alternatively about 100 mL,alternatively about 200 mL, alternatively about 0.5 Liters,alternatively about 0.75 Liters, alternatively about 1 Liter of coolingliquid. Depending on the cooling fluid used, these volumes of coolingfluid may provide cooling for approximately 10 minutes, alternatively upto 30 minutes, alternatively up to one hour.

Any non-vaporized liquid may then be allowed to run out the patient'snostrils 102. In some embodiments, a second balloon 250 may be mountedon the catheter 30 a proximal to the delivery ports to occlude thepatient's nostril 102. In an alternative embodiment, as shown in FIG. 5,one or both of catheters 30 a,b may further include a third lumen 170 influid communication with a suction port 70 proximal to the balloons 50a,b whereby the excess liquid may be suctioned from the patient's nasalcavity. In addition or alternatively, one or both nasal catheters 30 a,bmay include a third fourth lumen 135 extending between the distal andproximal ends of the catheter and having an opening at the distal andproximal ends and for providing a breathing passage through the nasalcavity while it is occluded by the balloons 50 a,b.

In an alternative embodiment, as shown in FIG. 10, the cooling assemblycomprises a single nasal catheter 232 having a balloon 250 mounted onthe distal end and a plurality of ports 40 a extending axially andlongitudinally on the distal region is advanced into the patient'snostrils 102 until balloon 250 is positioned proximal to the nasopharynx104. In this embodiment, the balloon 250 may be slightly larger thanballoons 50 a,b, or more compliant, such that when inflated balloon 250will conform to the opening to the nasopharynx 104 to seal the nasalcavity 100 from the rest of the patient's airways and preventnon-vaporized liquid from leaking into the patient's throat and toprevent inhalation of the fluid vapors. Fluid and/or pressure from thepressurized source 10 is delivered to the balloon 250 and the balloon250 is inflated to form a seal isolating the nasal cavity 100 from thenasopharynx 104. Once isolated, the spray of liquid 13 may be deliveredthrough delivery ports 40 into the patient's nasal cavity 100 andcirculated though the nasal cavity 100 to allow for rapid cooling of thepatient's head. The non-vaporized liquid may then be allowed to run outthe patient's other nostril. In an alternative embodiment, catheter 232may further include a third lumen having a port proximal to the balloon250 whereby the excess liquid may be suctioned from the patient's nasalcavity 100. In addition, catheter 232 may further include a third lumenextending between the distal and proximal ends of the catheter 232 andhaving an opening at the distal and proximal ends for providing abreathing passage through the nasal cavity while it is occluded by theballoon 250.

FIG. 5 illustrates one embodiment of a nasal catheter 30 having aballoon 50 mounted on the distal end and a plurality of delivery ports40 extending longitudinally and axially in the distal region fornon-invasive cerebral and systemic cooling of the nasal cavity. Nasalcatheter 30 is operably sized to extend through the patient's nasalcavity. Nasal catheter 30 has at least two lumens 142 and 154 extendingbetween proximal and distal ends of the catheters. Inflation lumen 154is in fluid communication with balloon 50 for providing pressure and/orfluid from the pressurized fluid source to balloon 50 for inflating theballoon 50. Delivery lumen 142 is in fluid communication with aplurality of ports 40 located along the outer wall of catheter 30 forspraying the fluid into the nasal cavity. In use, delivery lumen 142 isconnected to tubular member 41 for transporting the cooling fluid 13from the pressurized fluid source through catheter 30 and delivery ports40 into the patient's nasal cavity. These ports 40 are spaced apartlongitudinally and axially along the outer walls of catheter 30. Forexample, there may be about 10-40 delivery ports distributed around thecircumference of the catheter and spaced apart to cover the distancefrom about 3 cm to about 12 cm along the length of catheter 30. In use,when catheter 30 is placed in the nasal cavity of a patient, thisdistribution would provide full coverage of the nasal cavity. Thisdistinction is critical in that dispersing the spray over a largerregion permits greater cooling though evaporative heat loss.Furthermore, each of the plurality of delivery ports 40 will be designedso that the fluid flowing through the catheter lumen 142 will benebulized just prior to entering the nasal cavity. In some embodiments,as shown in FIG. 5, catheter 30 may further include a third lumen 170 influid communication with a suction port 70 proximal to balloon 50whereby the excess liquid may be suctioned from the patient's nasalcavity.

The ability to nebulize the liquid at each of the delivery ports 40ensures that the distribution of varying sizes of liquid particles willbe uniform throughout the nasal cavity. Specifically, when a liquid isnebulized, a spray with liquid particles of various sizes is created. Ifthe liquid was nebulized at the proximal end of the nasal catheter oroutside of the catheter and then transported as a nebulized liquid spraythrough the catheter lumen to the multiple delivery ports, the smallerliquid particles would flow through the proximal delivery ports whilethe larger liquid particles would be carried to the distal end of thetube before being delivered to the nasal cavity via one of the deliveryports near the distal end of the nasal catheter. This would result in anuneven distribution of the liquid particles within the nasal cavity.Conversely, when the liquid is transported through the nasal catheterand nebulized separately at each delivery port just prior to delivery,the size distribution of liquid particles distributed at any given pointin the nasal cavity is uniform. This is critical because an evendistribution of the varying sized liquid particles provides for betterevaporation of the liquid spray, which results in better cooling throughevaporative heat loss and is more tolerable to the patient

The balloon 50 is fabricated of a fully compliant, elastomeric materialsuch as blow molded polyurethane. In some embodiments, the balloon 50may be configured to have maximum or fully inflated, diameter of about10 mm, alternatively 15 mm, alternatively 20 mm, alternatively 25 mm,alternatively 35 mm depending upon the patient size and desired locationfor use of the balloon. For example, in some embodiments, the balloon 50would be inserted into each nostril and inflated until it conforms tothe choana (the paired openings between the nasal cavity and thenasopharynx) for creating a seal in the posterior naval cavity proximalto the nasal septum. Alternatively a single balloon may be advanced pastthe posterior nasal cavity and inflated diameter of about 25-35 mm tocreate a seal proximal to the patient's nasopharynx. The balloons may beadhesively bonded to the outside of the catheter shaft, or may bethermally bonded. Other suitable means of joining the balloons are alsocontemplated.

In some embodiments, as shown in FIG. 5, catheter 30 includes a thirdlumen 135 extending from proximal to distal ends of the catheter 30 andhaving proximal and distal openings such that lumen 135 provides apassage through the patient's nasal cavity while it is occluded byballoon 50. This third “breathing” lumen is in fluid communication withthe patient's nasopharynx, pharynx, larynx, and/or esophagus, enablingthe patient to breathe while the apparatus is inserted in the nasalcavity. Nasal catheter 30 also has rounded sealed tip 136 on the distalend, which seals the distal end of lumens 142 and 152 and provides asmooth surface to avoid damaging sensitive tissues.

FIGS. 6-8 illustrate alternative geometries for the delivery andinflation lumens of nasal catheter 30. The catheter shaft may be aunitary extruded multi-lumen tube which extends for the full length ofthe device, with the exception of the soft tip attached at the distalend. The multi-lumen tube is preferably formed of an extrudable polymer,such as Pebax, polyethylene, polyurethane, polypropylene, or nylon. Thelumen shapes may be varied, for example, depending upon the coolingfluid used and the amount of evaporation expected during delivery of thefluid. For example, as shown in FIG. 6, in some embodiments, thecross-sections of delivery lumen 142 and inflation lumen 154 may beequal sized circular lumens. The circular lumens 142 and 154 have anadvantage for being least kinkable design for a double lumen extrusion.Alternatively, as shown in FIG. 7, the cross-sections of delivery lumen143 and inflation lumen 153 may be equal sized semi-circular lumens. Thesemi-circular lumens 142 and 153 will pass more gas/fluid so that for agiven lumen area the semi-circular lumen extrusion can be smaller indiameter overall. Alternatively, as shown in FIG. 8, the cross-sectionsof delivery lumen 144 and inflation lumen 154 may be unequal sizedcrescent-shaped and circular lumens. Preferably the inflation lumen 154will be smaller than the liquid delivery lumen 144. This extrusion witha crescent shape delivery lumen 144 also has the advantage of being ableto make a wider range spray pattern for the delivery of the coolingfluid (if needed).

In an alternative embodiment, as shown in FIG. 3, the occlusion balloon150 and cooling fluid delivery may be provided on separate nasalcatheters 131, 132 inserted into both of the patient's nostrils. Here, afirst nasal catheter 132 has a balloon 150 mounted on the distal end anda second nasal catheter 131 has a plurality of delivery ports 40extending axially and longitudinally in the distal region. Nasalcatheter 132 has at least one lumen connected to tubular member 51. Insome embodiments, the distal end of nasal catheter 132 may extend distalof balloon 150 and a nasal catheter 132 may have a second lumen with anopening in the distal tip for providing the patient breathing accesswhile balloon 150 is occluding the nasal cavity. Nasal Catheter 132 hasa length sufficient to extend proximal to a patient's nasopharynx suchthat in use balloon 150 may be positioned proximal to the nasopharynxand be inflated to seal off the patient's nasal cavity from thepatient's pharynx and airways. Nasal catheter 131 may be slightlyshorter than nasal catheter 132 because nasal catheter 131 only needs toextend into patient's nasal cavity to deliver the cooling fluid throughdelivery ports 40. Nasal catheters 131, 132 may both be provided in avariety of lengths to accommodate the varying anatomy of patients,including pediatric and adult sizes. In use, nasal catheter 131 has atleast one lumen connected to tubular member 41. As discussed previously,fluid 13 from the pressurized source 10 is first delivered throughmanifold 20 and tubular member 51 to nasal catheter 132 to inflateballoon 150. Once the pressure from the pressurized source 10 exceedsthe balloon inflation pressure, check valve 22 opens and fluid 13 fromthe pressurized source 10 flows though manifold 20 and tubular member 41to nasal catheter 131 and is delivered through ports 40 onto the surfaceof the patient's nasal cavity.

Although the foregoing invention has, for the purposes of clarity andunderstanding, been described in some detail by way of illustration andexample, it will be obvious that certain changes and modifications maybe practiced which will still fall within the scope of the appendedclaims.

What is claimed is:
 1. A method for cerebral cooling, comprising thesteps of: providing a cooling assembly comprising: a first elongatetubular member adapted for insertion into a nasal cavity of a patientthrough a patient's first nostril, the first elongate tubular membercomprising a proximal end, a distal end, a lumen extending therebetween,and a plurality of ports in fluid communication with the lumen; a secondelongate tubular member adapted for insertion into a nasal cavity of apatient through the patient's second nostril, the second elongatetubular member comprising a proximal end, a distal end, a lumenextending therebetween, and a plurality of ports on the distal end ofthe second elongate tubular member in communication with the lumen; amanifold in fluid communication with the lumens of the first and secondelongate tubular members, the manifold further communicating with athird elongate tubular member; and a reservoir containing a pressurizedfluid in communication with the third elongate tubular member, whereinthe pressurized fluid comprises a propellant having a boiling point lessthan 22° C.; inserting the first elongate tubular member into apatient's nasal cavity through the patient's first nostril such that theplurality of ports are positioned in the nasal cavity; inserting thesecond elongate tubular member into the patient's nasal cavity throughthe patient's second nostril such that the plurality of ports arepositioned in the nasal cavity; and delivering the pressurized fluidonto a surface of the patient's nasal cavity by infusing the pressurizedfluid from the reservoir through the manifold, into the lumens andthrough the plurality of ports of the first and second elongate tubularmembers.
 2. The method of claim 1, wherein the pressurized fluid furthercomprises a cooling fluid having a boiling point less than 37° C.
 3. Themethod of claim 2, wherein cooling fluid having a bailing point lessthan 37° C. is selected from the group consisting of a perfluorocarbon,a hydrofluorocarbon, and a fluorocarbon.
 4. A method for cerebralcooling, comprising the steps of: providing a cooling assemblycomprising: a first elongate tubular member adapted for insertion into anasal cavity of a patient through a patient's first nostril, the firstelongate tubular member comprising a proximal end, a distal end, a lumenextending therebetween, and a plurality of ports in fluid communicationwith the lumen; a second elongate tubular member adapted for insertioninto a nasal cavity of a patient through the patient's second nostril,the second elongate tubular member comprising a proximal end, a distalend, a lumen extending therebetween, and a plurality of ports on thedistal end of the second elongate tubular member in communication withthe lumen; a manifold in fluid communication with the lumens of thefirst and second elongate tubular members, the manifold furthercommunicating with a third elongate tubular member; and a reservoircontaining a pressurized fluid in communication with the third elongatetubular member, wherein the pressurized fluid comprising a propellanthaving a boiling point less than 22° C. and a cooling fluid having aboiling point less than 37° C.; inserting the first elongate tubularmember into a patient's nasal cavity through the patient's first nostrilsuch that the plurality of ports are positioned in the nasal cavity;inserting the second elongate tubular member into the patient's nasalcavity through the patient's second nostril such that the plurality ofports are positioned in the nasal cavity; and delivering the pressurizedfluid onto a surface of the patient's nasal cavity by infusing thepressurized fluid from the reservoir through the manifold, into thelumens and through the plurality of ports of the first and secondelongate tubular members.